Manipulation of sheet material



Jan. 7, 1936. c. E. S-TAFFORD 2,026,754

MANIPULATION OF SHEET MATERIAL Filed Jan. 26, 1934 Patented. Jan. 7, 1936 UNITED STATES PATENT OFFICE 2,026,754

MANIPULATION or SHEET MATERIAh Charles Ernest StafionLSpondon, near Derby, England, assignor to Celanese Corporation of America, a corporation of Delaware Application January 26, 1934, Serial No. 708,396 In Great Britain February 8, 1933 18 Claims.

sheet material with edgeshaving novel characor may be moved both in ity both teristics.

According to the invention foil is slitalong a predetermined line by effecting relative motion along such line between the foil and a blunt in- ,strument extending through the foil. With the blunt instrument making anot inconsidrable angle with the line of severance, the foil iscut quite accurately and cleanly, notwithstanding the absence of a cutting edge on a considerable angle with the plane of the foil at the point where it pressesagainst it, the edge produced is of a serrated character, the profile of the serrations resembling saw teeth with rounded crests and hollows.

The cutting instrument may be held stationary directions in and out of the plane of the foil. Thus, stationary rods, wires, or the like may be used, or blunt edged discs extending through the foil and rotated if desired.

The serrated edge produced as described above gives the foil a distinctive and attractive appearance. 1

The serrations have quite a surprising regularas to pitch and depth, the edges of the "teeth being clear cut and of smooth, curved profile. This is probably due to the regular thickness and substantially homogeneous character of the material being severed, as ,is particularly the case in papers or foils produced by fiowing or otherwise depositing solutions of cellulose acetate or other cellulose derivatives, or viscose or cuprammonium solutions, and solutions of gelatin and similar materials, and causing them to set either by coagulation or evaporation. ,The .absence of fibre or grain from such materials enables them to part cleanly in any direction under the stresses set up by the blunt severing instrument.

The invention is capable of application in a variety of ways in the manufacture ,and/ or utilization of foils of the character mentioned. For example, it may be used to effect the cutting away of the thick edge usually produced in the manufacture of foils, and for this purpose may be carried out either continuously with the producthe instrument. Itthe face of the instrument is normal to or makes tion of the foil or as a separate operation on the completed foil. Thus, for example, the set foil may, in the apparatus in which it is produced, be engaged by a pair of blunt instruments such as rods, wires or like members suitably mounted to protrude through the foil inside the thickening which occurs over some distance from the edges of the foil. The foil is drawn past the rods under tension, so that the thickened edges are slit by the rods along lines parallel with the edges of the foil.

The severing instrument may be disposed normally to the plane of the foil or more or less inclined thereto. With such an arrangement the teeth of the serrations are slightly inclined in a direction opposite to that of severing, thus imparting an added novel characteristic to the edges formed by this methodof slitting,

The profile of the teeth varies somewhat with the position of the instrument relative to the plane of the foil. If an edge with teeth extending substantially normally to the edge of the foil is desired, thisefiect can be obtained by lightly folding the foil over on itself a1 ong the line along which severing is to be effected and drawing the severing instrument through the foilalong-the bend. The foil should not be nipped'or creased along the bend, however, or the edge formed at such points will follow a smooth, straight path.

-If desired, however, the slit edges may be formed with straight portions alternating with serrated portions. Such alternating effects as well as those resulting from continuous teeth can be incorporated with advantage in foils, or transparent papers, of viscose or cellulose acetate which are used chiefly for wrapping, ornamental, and

similar purposes, the edge imparting a distinctive and characteristic appearance thereto.

The foil-slitting process according to the invention is particularly advantageous in that the operation is simple and is quickly effected.- when treating foils in roll Thus, for example,

form,

mere unwinding of the foil and passage past the slitting instrument, or instruments, ex-

tending through the foil slit cleanly.

enablesgthe foil to be The operation may also, as explained above, .be carried out continuously with the production of the foil; The method is applicable to various thicknesses of foil, as well as to different types of foil. the foil may vary from ab 0.003 inch or so. The scribed in greater detail Thus the thickness of out 0.0005 inch to 0.001,

invention will now be dewith reference to the accompanying drawing in which:--

Fig. l is a perspective view of an apparatus operating to slit foil as it is being drawn from any suitable supply;

Figs. 2, 4 and 6 show various profiles obtained in foils slit by rods of the diameters illustrated in the adjacent Figs. 3, and '7 respectively, while Fig. 8 shows a further form of profile.

Referring to Fig. 1 a sheet of foil 4 is drawn by rolls 5 and Bfrom a roll, a casting surface or other source of supply (not shown), and passes over tension rods 1, 8, 9, ID to a winding core I I where it is wound into a roll I2. The pull of the roll I2 keeps the foil evenly tensioned between the rods 8, 9, and along this run of the foil vertical slitting rods I3, I3 are positioned so as to extend through the plane of the tensioned foil 4. The pulling of the foil past the rods I3 causes the foil to be slit longitudinally along lines parallel to the edges of the foil, the actual line of slitting, being sinuous, imparting to the slit edges serrations resembling curved saw teeth with rounded crests and hollows. With the foil held flat at bothsides of each rod, the teeth are inclined forwardly, i. e. in the direction of motion of the foil.

In the embodiment illustrated in Fig. 1 the rods I3, I3 are positioned so as to slit the foil near the edges of the sheet, the narrow strips I4, I4 so formed passing round the tension rod ID to winding cores I5, I5 where they are wound into rolls I6, I6. This type of apparatus is particularly suitable for use in trimming off the thick edges formed in foil manufacture mentioned above, the

trimmed strips being wound separately and used for ornamental or other purposes.

Any number of slitting rods can be used across the width of the foil to form strips of foil having serrated edges, the rods being arranged at appropriate distances apart in accordance with the width of strip desired. In this way the sheet can be converted into strips of suitable width for supplying wrapping or packaging machines, or packet or envelope making machines, or formed into rolls from which lengths can be severed to form blanks for wrapping purposes. Such blanks may be formed continuously with slitting. Again, quite narrow ribbons, e. g. of inch in width may be prepared for ornamental or' other purposes. As will be explained later, different forms of teeth are obtained by the use of different sizes and types of rods.

Various sizes of profile and pitch produced by cylindrical slitting-rods disposed substantially normally to the foil are illustrated in Figs. 2, 4

and 6, Fig. 2 showing foil I! having a relatively coarse profile obtained by the use of the slitting rod I8 having the diameter shown in Fig. 3, while Fig. 4 shows a foil I9 having a relatively fine profile, this type of edge being produced by the slitting rod 20 shown in Fig. 5.

Fig. 6 illustrates a relatively narrow band or ribbon 2I produced in the manner explained above and having serrations along both edges, the profile being of medium measurement when compared with the profiles of the foils shown in Figs. 2 and 4, and being obtained by the use of the slitting rods 22, 22 shown in Fig. 7. v

The sheets or strips may be slit with curved edges as illustrated in the foil 23 of Fig. 8, this effect being obtained by suitably guiding the rods as the foil is drawn past them.

In gen ral, serrations of small depth and pitch, of the type shown in Fig. 4, are produced by the use of a slitting rod of yery small diameter, say 1/50 of an inch, while, as indicated in the drawing much larger serrations can be produced with the aid of rods of larger diameter. For exslitting machine.

ample a rod of of an inch diameter gives serrations of about A; of an inch, while a rod of 4" diameter gives serrations of about of an inch in depth. [As shown in the drawings the edges of the-serrations are quite clean resembling cut edges, and the tips and roots of the teeth are of smooth rounded form. If an edge of varying pitch and profile is desired atapered slitting rod may be used, the rod being moved up and down in the foil in order to present to the foil a severing surface of varying diameter. It is found that foils of cellulose acetate are particularly suitable for treatment according to the invention the slit serrations being exceptionally uniform and clean.

It is therefore possible to provide a serrated edge for the sheet material which is ornamental in character and one which, moreover, where the material is to be used for packing purposes enables the edge to be readily and firmly sealed by the useof a suitable adhesive or solvent. It is to be observed, however, that care should be-taken in the production of relatively narrow ribbons that the slitting rod is not of too large a diameter, so as to avoid risk of the slit running out of line and breaking the ribbon.

While, by virtue of its shape and ease of manipulation, a rod is particularly suitable for use as the slitting instrument according to the invention, other blunt instruments also are efficacious. Thus, for example, bars, suitably sup- "v ported wires, cords, tapes, plates and similar members are found suitable for use as slitting instruments.

As will be evident from the foregoing the invention offers a very simple means for the slitting or trimming of foils and similar material. The operation can, moreover, be carried out quite rapidly, e. g. at speeds of 16 feet or more per minute. The slitting rods can be readily mounted in operative position, whether in the machine in which the foil is produced or in a separate Means are preferably provided for adjusting the positions, and if desired the number, of the rods, and it may also be arranged that the rods themselves are removable so that they can be placed in position after the foil has been led to a take-up roll or feed roller by which it is drawn taut. For example, the rods may be mounted on brackets adapted to swing clear of the foil and fitted with means to hold the rods rigidly in position when they have been caused to penetrate the foil.

What I claim and desire to secure by Letters Patent is:

1. The process of slitting foil of an organic material along a predetermined line which comprises extending a blunt instrument through said foil at a point in said line, and thereafter effecting relative motion along said line between said foil and said blunt instrument.

2. The process of slitting foil of an organic material along a predetermined line'which comprises extending a blunt instrument through said foil at a point in said line, holding said foil substantially plane where' the blunt instrument extends through the foil, and effecting relative motion along said line between said foil and a said blunt instrument.

3. The process of slitting foil of an organic material along a predetermined line which comline slit edges each comprising a row of teeth having a smooth, curved profile.

4. The process of slitting foil of an organic material along a predetermined line which comprises extending a blunt instrument through said foil at a point in said line, eilecting relativemotionalong said line between said foil and said blunt instrument,.and thereby iorming along said line slit edges each comprising a row of teethinclined with respect to the line of severance,and having a smooth, curved profile.

5. The process of slitting foil of an organic material along a predetermined line which comprises extending a cylindrical rod through the foil at a point in said line. effecting relative motion along said line between said foiland said rod, and thereby forming along said line slit edges each comprising a row of teeth having a smooth, curved profile.

6. The. process of slitting foil of, an organic material along a predetermined line which comprises lightly iolding the foil along said line, extending a blunt instrument through said foil at the fold,- and thereafter effecting lelative motion along said fold between said foil and said instrument. '7.'The process of slitting foil of an organic material along a predetermined line which comprises extending a blunt instrument through said foil at a point in said line, andthereafter drawing the foil past the blunt instrument in the 8811-.

eral direction of said predetermined line.

8. The process of slitting a sheet of foil of an organic material into strips along predetermined lines, which comprises extending a blunt'instru- 'ment through said sheets at a point in each of said lines, and effecting relative motion between said foil and each or said blunt instruments along the corresponding predetermined line.

9. Process according to claim 8, comprising disposing said blunt instruments normally to the plane of the foil so as .to impart to the strips produced edges each comprising a row of teeth inclined with respect to the line of severance, and having a smooth curved profile. 1

10. The processof slitting foil of an organic material along a predetermined line which comprises supporting said foil, extending a blunt instrument through said supported foil at a point in said line, and feeding said foil-under tension past saidblunt instrument in the general direction of said predetermined line, thereby formingalong said line slit edges each comprising a row of teeth having a smooth curved profile.

11. Process for the treatment of foil of an organic material which comprises trimming oif along predetermined lines the irregular edges formed in the manufacture of foil, by extending a blunt instrument through said foil at a point 5 in each 0! said lines, and thereafter eifecting relative motion between said foil and each of said blunt instruments along the corresponding predetermined line.

12. The process of slitting cellulosic and cellu- 1o lose ester foils along a predetermined line which comprises extending a bluntinstrument through said. foil at a pointin said line, eflecting rela tive motion along said line between said foil and said blunt instrument, and thereby forming along said line slit edges each comprising a row of teeth having a smooth, curved profile.

13. The process of imparting a toothed edge to foil of organic derivatives of cellulose, which comprises extending a rod through said foil? and drawing said rod along a line along which the toothed edge is desired. I

14.'Apparatus for slitting foil of an organic material comprising means adapted to hold the foil under tension, a blunt instrument extending through the foil and means for imparting rela-' tive motion along the foil between the instrument and the foil.

15. Apparatus for slitting foil of an organic material comprising means forfeeding forward 0 the foil, means for maintaining the 'foil under tension, and a blunt instrument extending through the foil and past which the foil is drawn to be slit. i

16. Apparatus for slittingjoil of an organic 5 material, comprising means for feeding forward the foil, means for maintaining the foil under tension, a blunt instrument extending through the foil, and a winding roll adapted to draw the tensioned foil past the bluntinstrument so as 40 to slit the i0 4 17. Apparatus for slitting foilof an organic material comprising a plurality of tension rods disposed parallel to each other, means to draw a length of foil over said tension rods, and at 5 .least one blunt instrument extending through the plane of the foil between the tension rods so as to slit the foil as it is drawn past the e instrument.

18. Apparatus according to claim 1'7, in which 5 said means to draw said length of foil over said tension rods comprises a "plurality of receiving 7 rolls which wind the separate widths into which the foil is slit.

CHARLES ERNEST STAFFORD. 5a 

